Kevin has an equal number of dimes, nickels, and quarters in his piggy bank. he randomly picks a coin, replaces it, and picks another coin. what is the probability that the sum of the two coins picked is at least 30 cents?

You coordinate volunteers for litter cleanup in local parks. your spreadsheet lists drivers and the number of seat belts in each driver’s car. the spreadsheet calculates the number of drivers (d) and the total number of seat belts (s). you want to know the maximum number of volunteers, besides drivers, that can be transported to the park in a single trip given that each person must have a seat belt of their own.